Construction of rotating wheels for rotary fluid-compressors.



A. HUGUENIN. GONSTRUGTION 0F ROTATING WHEELS FOR ROTARY FLUID GOMPRESSORS.

APPLICATION FILED NOV. 5, 1907.

Patented May 17, 1910 2 SHEETS-SHEET 1.

' A. HUGUENIN. CONSTRUCTION OF ROTATING WHEELS FOR ROTARY FLUID GOMPRESSORS.

APPLICATION FILED NOV. 5, 1907.

1 Q9 I Patented May 17, 19110. 2 snnms-snrzm 2.

ALBERT HUGUENIN, or

aarr @FFIQE.

ZURICH, SWITZERLAND.

Specification bf Letters ma.

Patented May 17, 1914).

Application filed November 5, 1907.- Serial No. 400,808.

To all whom it may concern:

Be it known that I, ALBERT HUGUENIN, of Zurich, a citizen of Switzerland, and whose post-oflice address is 33 Universitatsstrasse, Zurich, Switzerland, have invented new and useful Improvements in the Construction of Rotatin Wheels for Rotary Fluid-Gompressors, 0 which the following is the specification.

This invention relates to improvements in the construction of the radial wheels for rotary fluid compressors, having a cylindrical or pyramidal slot surface concentric with the axis of rotation. .As is well known these wheels have the great advantage of enabling the elastic fluid to be compressed without, the production of shocks or eddies. It is well known that the use of shrunk rings for holding the single blades or arms of the wheel involve the drawbacksthat they have to be arranged at'both sides of the blades and made cylindrical; and, for the purpose of leaving free a sufiiciently large inlet cross section, they must be made of such large diameter that their speed of rotation leaves a very small margin of safety. In that way a very heavy construction is produced which must be considered impracticable owing to the fact that the most important part of the. structure affords the smallest de es of safety. In addition to that it is 0' course necessary to (provide a hub for driving the two rings an the arms.

In the accompanying drawings which illustrate apparatus embodying this invention Figure l is a central section of a rotary fluid compressor; Fig. 2 is a perspective view of one of the arms or blades; Fig. 3 is a section of certain insertions or spacersand Fig.

3 is an elevation .of the same; Fig. 4 is a .central section of the hub portion of the device, and Fig. 4: is an elevation of the same; Fig. 5 is a detail showing the angle at which the blades are out. i

In addition to the disadvantages already referred to above, if it is desired to make the hub a carrying element, the following1 difliculties are met with (see Fig. 1) :By-t e one sided inlet an entirely unsymmetrical blade surface at is caused so that the resultant ofthe centrifugal force on the blades is situated outside the central radial line of the outlet channel and of the adjoining diffuser b. The blades in themselves must, however, be held in a projection c which is flush with the right handside of the blade surface a,

cal reasons in erecting. As, on the other hand the longitudinal extent of the projection 0 is limited by the length of the inlet edge d of the blades, determined by the quantity to be handled, it will be seen at once that the radial central line (or central plane) of the said projection 0 will not coincide with the direction of the resultant centrifu- 'gal force of the whole arm. This results therefore in the projection 0 having to withstand not only the tension corresponding to the centrifugal force, but also a bending moment which is transmitted direct to the hub. This condition is not only undesirable having regard to dimensions of the said important parts, but it is also very dangerous as any small deformation at once results in a reduction of the axial clearance between the blade surface a and the fixed wall 6 which would considerably decrease the safety of working. v

This invention consists in the formation of the armin such a way that notwithstandingthe use of a one-sided inlet and a pyramidal slot surface, the resultant o the centrifugal force on the arms as a whole is arranged to coincide exactly with the radial central line (or radial central plane) of the projection c. Ihis result is obtained in the following. manner: The blade surface a is machined on both sides in the direction of the arrow shown in Fig. 1, by means of a \milling cutter, the cutting, edge of which is inclined as shown in Fig. 5, and the blade surface thus receives a thickness gradually decreasing outward from the projection 0 in a direction transversely to the advance of the work. By a suitable method of guid:

ing, provision is made "for a continual de this being absolutely necessary for practicrease in the thickness of the blade from the inlet to the outlet edge. In that way the resultant of the centrifugal force of the blades alone is shifted as much as possible to the right in Fig. 1. In order to balance the arm completely, that is to say to bring the total resultant centrifugal force to coincide with the radial central plane of the projection c (which is of the same thickness throughout) each blade is provided on the right hand side with a thickened portion a, the centrifugal force of which effects the de-, sired equalization. In that way any bendin moment on the projection c is avoided.

he blade is heldin the hub 12 by means of a cylindrical thickened portion a engaging with a corresponding recess f in the hub. The arm is shown separately in Fig. 2 perspective. The hub 32 has a cross section shown in Fig. 4 and is provided with perforations f and slots 9 for receiving the single arms. In order to give the whole construction of the wheel the necessary rigidity in a circumferential direction, more particularly in order to avoid as far as possible any vibration, insertions or spacers it are placed between the arms, which spacers on the one hand are held in the groove is of the hub and on the other hand are screwed at l to the boss of the-arm, whereby each spfiper is forced strongly against the two ar s and at the same tlmethe spacers form the limit of the fluid. conduit toward the hub. These spacers h are obtained by cutting a disk i of the required cross section (see 3). The thickened portions or bosses a. of the arms secure them against movement to the left (Fig. '1) they being restrained against movement in this direction by. the hub p, the slots 9' in which 'are too narrow to permit their passage, and at the same time'they are prevented from moving to the right by the nut g screwed on the hub -p. The method of keylng and longitudinally' fixing the wheel on the shaft renders any collars and any screw thread su erfluous and makes it possible with a small alteration in the diameter of the shaft, to assemble and take to pieces the single wheels of a eaaiae -multiple compressor in an easy and reliable manner. Thls method of keying and longithe ub, the projections and the blades, sub- I ,stantially as set forth.

2. In rotating compressors the combination with blades radually decreasing in section outward and lengthwise, of lateral triangular projections attached to the hub, to which said blades are secured, of sectorshaped s acers separated from one another by radia slots which receive the blades, and

of a case adapted to receive the wheel composed by the hub the projections and the blades, substantially as set forth.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

ALBERT HUGUENIN.

Witnesses: I I

' A. LIEEBERKNECHT,

ALFR. WIESTAND. 

